Ans. :1) Montmorillonite Clay-
A calcium aluminum silicate type of hydrous clay which is ground, processed and bagged. It is a naturally occurring non-hazardous substance. Clay, the least expensive of all desiccants, is used in most industrial applications
requiring humidity control.
2) Silica Gel-
A form of silica manufactured from sodium silicate and sulfuric acid. Like Clay, Silica Gel is non-hazardous and
is capable of adsorbing 40% of its weight in water vapor
at 100% humidity. Silica Gel has a porous molecular structure that closely resembles a sponge, and has the highest capacity of any commercial desiccant for
moisture adsorption.
3) Molecular Sieve-
A manufactured crystalline version of Zeolite containing a network of uniform pores and empty cavities. Molecular sieve is derived from sodium, potassium or calcium alumina silicate. It is a non-hazardous material. Molecular sieve is the desiccant of choice for the most demanding and unique applications. Molecular sieve is the most aggressive and expensive of the primary desiccants.
*Carbon-Although not a desiccant, Carbon is often used alone
or in blends in packaging applications where odor is an issue
(i.e. vitamin packaging).